This project will use a one compartment pharmacokinetic model to predict gentamicin peaks and troughs in neonates. If the results of this study can consistently correlate particular variables, such as asphyxia or respiratory distress syndrome, with changing gentamicin clearance in the neonate, it would allow the formulation of more appropriate recommendations for gentamicin therapy, and would decrease the incidence of both toxic and subtherapeutic blood levels in newborn babies.